Diesel Particulate Filter - Particulate Matter

In a theoretically perfect combustion, carbon dioxide, water and nitrogen are the end products.

In reality, the incomplete combustion of diesel fuel results in emissions that include oxides of nitrogen (NOx), carbon monoxide (CO), carbon dioxide (CO2), water (H2O) and unburned hydrocarbons (HC). There are also unburned carbon particles, as well as engine oils, soot and ash particulates, which are known as particulate matter (PM).

The diesel particulate matter (DPM) id the visible cloud of black smoke that appears from engine start-up and continues to appear when engine is running.

Before the advent of Diesel Particulate Filters (DPF’s), soot particles were releases into the atmosphere at the end of the combustion process causing health and air quality problems. DPF’s are fitted after that catalytic converter to trap these particles. DPF filter also play a small part in the reduction off noise between 10-12DB. The diameter of the soot particles are close to 0.09 microns, which are made mainly by carbon and hydrocarbons. The principle of the Diesel Particulate Filter (DPF) is to collect the sooty particles and periodically burn them off. It needs to be noted that the lifespan (operation interval) of the DPF/catalyst combination is between 8000 and 12000 engine hours. The natural combustion of those particles takes place around 550°C. This is known as passive regeneration.
  • Diesel Emission gasses:
  • HC – Hydro Carbon - unburnt fuel particle
  • CO – Carbon Monoxide – Partially burnt fuel particle
  • CO₂ - Carbon Dioxide – a green gas (GHG) by-product of the combustion process
  • NO – Nitrous Oxide – a harmful gas
  • NO₂ - Nitrogen Dioxide – a harmful gas
  • O₂ - Oxygen
  • D.P.M – a harmful gas

Passive regeneration accurse between 550°C and 600°C degrees. The engine needs to run at these temperatures for a minimum of 60% of engine working time to ensure regeneration, If this regeneration does not occur, there is a build-up of soot which will lead to the backpressure in the exhaust system to rise.

If this situation occurs the DPF filter will need to be removed from the machine and baked at 800°C for 8 hours, all depending on the level of clogging that has accrued. Air is then used to pulse through the filter to remove the remaining ash.

The baking of the DPF filter need to be conducted by Rush Exhaust & Rush Enterprises for the interim, on an exchange base, to reduce costs. Were a retrofit unit can be used.

For every 10 DPF filter in used a recommended 3 Units should be on standby to eliminate any down time, in the production line

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